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Java Source | 2000-05-25 | 5.7 KB | 174 lines |
- //: CADState.java
- //////////////////////////////////////////////////
- // Copyright (c) Bruce Eckel, 1998
- // Source code file from the book "Thinking in Java"
- // All rights reserved EXCEPT as allowed by the
- // following statements: You can freely use this file
- // for your own work (personal or commercial),
- // including modifications and distribution in
- // executable form only. Permission is granted to use
- // this file in classroom situations, including its
- // use in presentation materials, as long as the book
- // "Thinking in Java" is cited as the source.
- // Except in classroom situations, you cannot copy
- // and distribute this code; instead, the sole
- // distribution point is http://www.BruceEckel.com
- // (and official mirror sites) where it is
- // freely available. You cannot remove this
- // copyright and notice. You cannot distribute
- // modified versions of the source code in this
- // package. You cannot use this file in printed
- // media without the express permission of the
- // author. Bruce Eckel makes no representation about
- // the suitability of this software for any purpose.
- // It is provided "as is" without express or implied
- // warranty of any kind, including any implied
- // warranty of merchantability, fitness for a
- // particular purpose or non-infringement. The entire
- // risk as to the quality and performance of the
- // software is with you. Bruce Eckel and the
- // publisher shall not be liable for any damages
- // suffered by you or any third party as a result of
- // using or distributing software. In no event will
- // Bruce Eckel or the publisher be liable for any
- // lost revenue, profit, or data, or for direct,
- // indirect, special, consequential, incidental, or
- // punitive damages, however caused and regardless of
- // the theory of liability, arising out of the use of
- // or inability to use software, even if Bruce Eckel
- // and the publisher have been advised of the
- // possibility of such damages. Should the software
- // prove defective, you assume the cost of all
- // necessary servicing, repair, or correction. If you
- // think you've found an error, please email all
- // modified files with clearly commented changes to:
- // Bruce@EckelObjects.com. (Please use the same
- // address for non-code errors found in the book.)
- /////////////////////////////////////////////////
-
- // Saving and restoring the state of a
- // pretend CAD system.
- import java.io.*;
- import java.util.*;
-
- abstract class Shape implements Serializable {
- public static final int
- RED = 1, BLUE = 2, GREEN = 3;
- private int xPos, yPos, dimension;
- private static Random r = new Random();
- private static int counter = 0;
- abstract public void setColor(int newColor);
- abstract public int getColor();
- public Shape(int xVal, int yVal, int dim) {
- xPos = xVal;
- yPos = yVal;
- dimension = dim;
- }
- public String toString() {
- return getClass().toString() +
- " color[" + getColor() +
- "] xPos[" + xPos +
- "] yPos[" + yPos +
- "] dim[" + dimension + "]\n";
- }
- public static Shape randomFactory() {
- int xVal = r.nextInt() % 100;
- int yVal = r.nextInt() % 100;
- int dim = r.nextInt() % 100;
- switch(counter++ % 3) {
- default:
- case 0: return new Circle(xVal, yVal, dim);
- case 1: return new Square(xVal, yVal, dim);
- case 2: return new Line(xVal, yVal, dim);
- }
- }
- }
-
- class Circle extends Shape {
- private static int color = RED;
- public Circle(int xVal, int yVal, int dim) {
- super(xVal, yVal, dim);
- }
- public void setColor(int newColor) {
- color = newColor;
- }
- public int getColor() {
- return color;
- }
- }
-
- class Square extends Shape {
- private static int color;
- public Square(int xVal, int yVal, int dim) {
- super(xVal, yVal, dim);
- color = RED;
- }
- public void setColor(int newColor) {
- color = newColor;
- }
- public int getColor() {
- return color;
- }
- }
-
- class Line extends Shape {
- private static int color = RED;
- public static void
- serializeStaticState(ObjectOutputStream os)
- throws IOException {
- os.writeInt(color);
- }
- public static void
- deserializeStaticState(ObjectInputStream os)
- throws IOException {
- color = os.readInt();
- }
- public Line(int xVal, int yVal, int dim) {
- super(xVal, yVal, dim);
- }
- public void setColor(int newColor) {
- color = newColor;
- }
- public int getColor() {
- return color;
- }
- }
-
- public class CADState {
- public static void main(String[] args)
- throws Exception {
- Vector shapeTypes, shapes;
- if(args.length == 0) {
- shapeTypes = new Vector();
- shapes = new Vector();
- // Add handles to the class objects:
- shapeTypes.addElement(Circle.class);
- shapeTypes.addElement(Square.class);
- shapeTypes.addElement(Line.class);
- // Make some shapes:
- for(int i = 0; i < 10; i++)
- shapes.addElement(Shape.randomFactory());
- // Set all the static colors to GREEN:
- for(int i = 0; i < 10; i++)
- ((Shape)shapes.elementAt(i))
- .setColor(Shape.GREEN);
- // Save the state vector:
- ObjectOutputStream out =
- new ObjectOutputStream(
- new FileOutputStream("CADState.out"));
- out.writeObject(shapeTypes);
- Line.serializeStaticState(out);
- out.writeObject(shapes);
- } else { // There's a command-line argument
- ObjectInputStream in =
- new ObjectInputStream(
- new FileInputStream(args[0]));
- // Read in the same order they were written:
- shapeTypes = (Vector)in.readObject();
- Line.deserializeStaticState(in);
- shapes = (Vector)in.readObject();
- }
- // Display the shapes:
- System.out.println(shapes);
- }
- } ///:~